A splicing tape can be used, for example, as a flying splice for splicing a new roll of paper to an expiring, running sheet or web of a depleting roll of paper. The splicing tape is first attached to the top sheet of a new roll. Then, the new roll is accelerated to the speed of the running web using, for example, a belt drive. Finally, the splicing tape on the new roll is brought into contact with the expiring web. When the splicing tape is brought into contact with the expiring web, the new roll adheres to the expiring web causing the new roll to be spliced to the expiring web. U.S. application Ser. No. 10/274,268, which is incorporated herein by reference, discloses an example of such a splicing tape.
FIGS. 1a and 1b each show a belt drive 350 having a belt 351 used to accelerate a new roll of paper or other material 210 in the direction of arrow “A”. This technique is employed, for example, in the commercial printing and newspaper markets. The belt drive 350 is lowered onto the new roll 210 so that the belt 351 contacts with the new roll 210 at a corresponding belt contact area 260. When the belt drive 350 is operated to rotate the belt 351 while in contact with the new roll, the new roll 210 rotates.
As shown in FIG. 1a, the new roll 210 includes a splicing tape 140 laid across the new roll along an axial direction X of the new roll. Since the splicing tape is laid over a part of the contact area 260, the belt 351 will contact the splicing tape 140 when it is lowered to drive the new roll. However, allowing the belt 351 to contact the splicing tape 140 can cause significant problems. One such problem occurs when the splicing tape 140 is attached, as shown in FIG. 1a, to both the top sheet 211 of the new roll 210 and to the sheet 212 underlying the top sheet 211.
As shown in FIG. 1a, the splicing tape 140 can be an “all in one” type that has adhesive on both sides, such as that described in U.S. application Ser. No. 10/274,268. Alternatively, as shown in FIG. 1b, the splicing tape 140′ can be a single sided, adhesive coated tape fixed on underlying sheet 212 with tab tapes 140a that are broken when the splicing tape 140′ is contacted on expiring web 220. Either arrangement allows the new roll 210 to splice with an expiring web sheet. However, since the splicing tape 140 (140′) is typically placed along the width of the new roll 210 (i.e., parallel to the axis X), the belt 351 of the belt drive 350 will contact or roll over a portion 141 of the splicing tape 140 (140′) that is positioned along the belt contact area 260 of the new roll 210. When the belt 351 rolls over the splicing tape 140 (140′), the adhesive of the splicing tape 140 (140′) tacks onto or adheres to the belt 351, causing the splicing tape 140 (140′) to prematurely release from the underlying sheet 212. Premature release of the splicing tape 140 (140′), or a portion of the splicing tape, can have a detrimental effect on the proper splicing of the new roll 210 to the expiring web sheet. In particular, the premature release of the splicing tape 140 (140′), or a portion of the splicing tape, can cause the top sheet 211 of the new roll 210 to be moved from the proper position for splicing with the expiring web.
Bridge labels have been used to overcome this problem. A bridge label is typically a die cut tab that is applied on top of a splicing tape at the portion of the splicing tape that would otherwise contact the belt of the belt drive. When properly applied, the bridge label will have an exposed lower tack surface with a lower adhesive strength than that of the splicing tape so as to provide some tack to the expiring web when the new roll is spliced to the expiring sheet without causing the splicing tape to release from the underlying sheet. If the bridge label did not have any exposed adhesive, the splice between the new roll and the expiring web at the position of the bridge label would pucker. This pucker could cause the splice to fail.
FIGS. 2a and 2b show a conventional bridge label 100 having an adhesive layer 120 and a non-adhesive (i.e., non-tacky) layer 130 provided on top of the adhesive layer 120. The non-adhesive layer 130 has ¼ inch diameter holes 126 that are spaced at intervals of ½ inch. As a result of this configuration, adhesive dots 122 from the adhesive layer 120 extend through the holes 126 to provide some adhesiveness, adhering the bridge label 100 to the expiring web when the new roll is spliced to the expiring sheet. On the other hand, the adhesiveness of the bridge label 100 is not strong enough to cause the bridge label 100 to adhere to the belt 351 so that the splicing tape 140 does not prematurely release from the underlying sheet 212.
U.S. Pat. No. 6,488,228, which is fully incorporated herein by reference, discloses another method of preventing the splicing tape from adhering to the belt drive. In accordance with this patent, a portion of the release liner is maintained on the splicing tape at a position corresponding to where the belt drive contacts the new roll. In accordance with this method, the bridge label does not have any exposed adhesive and the splice between the new roll and the expiring web may pucker at the position of the bridge label as explained above.
Referring to FIG. 3, aspects of a printing operation on a spliced web 200 will be described with respect to the splicing tape 140 of FIG. 1a. As shown in FIG. 3, the spliced web 200 includes the expiring web sheet 220, the end of the top sheet 211 of the new roll 210, and the splicing tape 140 and bridge label 100 that splice the top sheet 211 to the expiring web sheet 220. During the printing operation, the spliced web 200 is sent through a dryer to dry the inks on the web and burn off the ink solvents. As the spliced web 200 is moved forward in the direction of arrow “B,” high temperature (e.g., 350-400 degrees Fahrenheit) air 500 is directed toward the spliced web 200 to dry the ink.
However, when a conventional bridge label 100 is sent through the dryer, the bridge label 100 acts as an air dam since the splice portion at the bridge label is thicker than the remaining splice. The air dam causes the air 500 that builds up at the bridge label to become so hot that the adhesive of the bridge label 100 melts. As schematically illustrated in FIG. 4, this problem is further exacerbated in the case of the conventional bridge label 100 of FIGS. 2a and 2b. When this bridge label is sent through the dryer, the adhesive dots 122, which extend through the holes 126 of the non-adhesive layer 130 and which are adhered to the expiring web 220, further obstruct the flow of air 500 and raise the temperature of the hot air 500 that has entered the space between the bridge label 100 and the expiring web 220.
Furthermore, since the adhesion of the bridge label 100 to the expiring web 220 is lower than that of the splicing tape 140 due to a reduced contact area, it is easy for the bridge label 100 to be peeled off of the expiring web 220 by the force from the flow of air 500. In fact, if one of the adhesive dots 122 of the conventional bridge label 100 is peeled off the expiring web 220, it becomes more likely that an adjacent dot 122 will also be peeled off since the stress that is holding the paper is thereafter concentrated on the remaining dots 122. Eventually, all of the adhesive dots 122 are likely to be peeled off the expiring web 220. The resulting lack of adhesion along this portion of the splice causes the splice 140 to pucker and break in a manner similar to when a bridge label without exposed adhesive is used.
In short, the bridge label has the dual functions of preventing the splice from adhering to the belt of belt drive, while also providing adequate adhesion between a new roll and expiring web. However, conventional bridge labels have not adequately performed these two competing functions well.